Patent GB-544645-A (GB)
Title: Improvements in or relating to photographic sensitising dyestuffs
IPC: C09B23/12
Filed: 1940-10-16
Abstract: 544,645. Cyanine dyes ; photographic sensitisers. KENDALL, J. D., and FRY, D. J. Oct. 16, 1940, No. 15357. Sample furnished. [Class 2 (iii)] [Also in Group XX] Cyanine dyestuffs are prepared by condensing an alkyl or aralkyl quaternary salt of a compound having the formula : wherein R 1  is an alkyl or aralkyl group, R 2  is hydrogen or an alkyl, aralkyl or aryl group, R is hydrogen or an alkyl, aralkyl, aryl or heterocyclic group, R 4  is hydrogen or an alkyl group, A is oxygen or an NR 5  group (R 5  being an alkyl, aryl, aralkyl or heterocyclic group), D is the residue of a heterocyclic nucleus, n is 0 or 1 and x is 0, 1, 2 or 3, with the quaternary salt of a heterocyclic nitrogen compound containing an α or γ re-active thioether, selenoether or a (CH =CH)mNH  2  group wherein a hydrogen atom of the NH 2  group may be substituted by an acyl, aryl, or acylaryl group and m is 1, 2 or 3. The quaternary salts having the above general formula may be prepared by the processes described in Specifications 519,895, 528,803 or 544,647 and isoxazolones having the said formula may be obtained by re-acting acetoacetic ester oxime with a suitable ketone and re-acting the product with a quaternary salt of a heterocyclic. nitrogen compound having a re-active α or y thioether, selenoether or aminovinyl group. These compounds may belong to the thiazol, thiazoline, oxazol, oxazoline, selenazol, selenazoline, pyridine, quinoline, indolenin, pyrimidine, thiodiazol and quinazoline series. The diazines described in Specification 425,609 are also mentioned. When, of the three nuclei present in the products, one is a pyrazolone or isoxazolone nucleus and the other two are of the same nature as one another, the dyestuffs may be prepared directly by condensing in the presence of an alkyl or aralkyl ester two molecular proportions of the heterocyclic nitrogen compound containing a, re-active thioether, selenoether or aminovinyl group with a pyrazolone or isoxazolone having the formula R 2 , R 3 , R 4  being as above defined. The products sensitize. gelatine silver halide photographic emulsions. In examples in which the condensations are effected in the presence of methyl or ethyl p-toluenesulphonate for the formation of quaternary salts : (1) 1-methylthiolbenzthiazol is condensed with α(2-methyldihydrobenzthiazolylidene) 4<SP>1</SP>-isobutylidene-1<SP>1</SP>- phenyl-31-methyl-51-pyrazolone, and α(2-methyl (and ethyl) dihydrobenzthiazolylidene) 41-isopropylidene - 1<SP>1</SP> - phenyl - 3<SP>1</SP> - methyl - 51 - pyrazolone, α (2 - methyldihydrobenzthiazolylidene) 4<SP>1</SP> - isopropylidene - 3<SP>1</SP> - methylisoxazolone, S (1 : 3 : 3 - trimethylindolylidene - α- methyl - 2 : 4<SP>1</SP>- butenylidene - 3<SP>1</SP> - methyl - 51 - isoxazolone, α (2 - methyldihydrobenzthiazolylidene) 41 - isopropylidene - 11 - phenyl - 31 -furyl - 5<SP>1</SP> - pyrazolone and with y - (2 - methyldihydrobenzthiazolylidene) - 4<SP>1</SP> - isobutylidene - 1<SP>1</SP> - phenyl - 3<SP>1</SP> - methyl - 5<SP>1</SP> - pyrazolone ; (2) α (2- methyldihydrobenzthiazolylidene) 4<SP>1</SP> - isopropylidene --11 - phenyl - 3<SP>1</SP> - methyl - 51 - pyrazolone is condensed with 2<SP>1</SP>- #-acetanilidovinyl -3 :3 - dimethylindoleninemethiodide, 1 - # - acetanilidovinylbenzthiazolethiodide, 2 - methylthiolquinolineethyl-p-toluenesulphate, 1 - methylthiolbenzoxazolethyl - p - toluenesulphonate, 1 - methylthiol - 5 : 6 - naphthathiazolethyl - p - toluenesulphonate, 4 - acetanilidovinylquinolinemethiodide or ethiodide ; (3) α (2 - ethyl - 5 : 6 - naphthathiazolylidene) 4<SP>1</SP> - isopropylidene - 3<SP>1</SP> - methyl - 5<SP>1</SP> - isoxazolone is condensed with N-ethylquinoline-4-thione. In further examples the products are obtained directly from one molecular proportion of the pyrazolone intermediate, two molecular proportions of the heterocyclic nitrogen compound containing the α or y re-active group and an alkyl or aralkyl ester. 1-Phenyl-3-methyl-4- isopropylidene-5-pyrazolone is thus condensed with 1-methylthiolbenzthiazol, 1-methylthiol- 4 : 5 - dimethoxybenzthiazol, 1-methylthiol - 4 - chlorbenzthiazol, 1 - methylthiolbenzoxazol and 1 - methylthiol - 5 : 6 - naphthathiazol and 3 - methyl - 4 - isopropylidene - 5 - isoxazolone with 1 - methylthiol - 5 : 6 - naphthathiazol and 1-methylthiolbenzoxazol. The conversion of some of the ethyl-p-toluenesulphonates to bromide, iodide and perchlorate is described. A sample has been furnished under Sect. 2 (5) of the Acts of a dyestuff prepared by condensing 1 - methylthiol - 5 : 6 - naphthathiazol - methyl-p-toluenesulphonate with an intermediate prepared from 1-methylthiolbenzthiazolmethyl-p-toluenesulphonate and 1-phenyl- 3 - methyl - 4 - benzylmethylmethylene - 5 - pyrazolone.